Synthetic resin and method of making the same



name a... 22, 1938 I PATENT OFFICE smnn'rro aasm AND METHOD MAK- AME GTHES James Victor Hunn, Chicago, 111., alsignor to The Sherwin-Williams Company, Cleveland, Ohio, a corporation of Ohio No Drawing. Application June 21, 1935, Serial No. 27.741

The present invention relates to alkyd resins of the oil acid modified, oil-soluble type, and has for its general object to provide an improved- -process for producing a homogeneous oil-soluble resin wherein the polybasic acid consists of maleic acid or its anhydride.

In spite of numerous statements and intimations to the contrary in the patent and other literature, I have found that maleic acid cannot be substituted for phthallc acid in the well known reaction involving glycerol, phthalic acid, and the acids of a fatty tri-glyceride, such as the acids of a drying oil.- Thus, I have found that when glycerol, maleic acid and the acids of linseed oil are reacted in such proportions as would yield a homogeneous oil-soluble resin in the case of phthalic acid, a two-layer system results, composed of an insoluble resinous material and an upper oily layer. These two materials are noncompatible and cannot bemade to mix into a homogeneous mass even with continued careful heating and constant agitation. Ultimately, the oil-insoluble mass gels and finally chars at the bottom of the container.

I have, however, found that if maleic acid is heated with a high molecular weight fatty acid having more than one double bond, such as the more highly unsaturated acids contained in linseed, China-wood, and other drying fatty oils for a suitably long time and at a sufliciently high temperature, the mixture of acids can be subsequently' reacted with glycerol to yield a homogeneous resinous material which is soluble in varnish oils. This preliminary heating of the maleic acid (or anhydride) with the highly unsaturated fatty oil acids (that is, more unsaturated than oleic acid) must be conducted far beyond the point at which these acids mingle into a homogeneous mixture. The heating must, in fact, continue at high temperatures long beyond this fusion and mingling is secured. Thus, in the case of the acids obtained from linseed oil, the heating with the maleic acid should take place at about. 360 F. for about 45 minutes, or even more. What the nature of the reaction between the maleic acid and the linseed oil acids may be, cannot be definitely determined, but that some reaction takes place must be concluded from the fact that the acid reaction mass, upon the addition thereto of the necessary quantity of glycerol, will produce a homogeneous resinous material, whereas the addition of glycerol to a mass of maleic acid and linseed oil acids which has been heated only to the point required to melt the 56 maleic acid and cause it to mingle with the linseed oil acids, will result in the aforementioned two non-compatible materials.

It will be understood that it is not necessary to employ fatty oil acids containing two or more double bonds, or a triple bond, in the pure-state. but that the crude mixture obtained upon hydrolysls of various drying and semi-drying oils may be employed.

The invention will be further described with the aid of the following example which is presented purely for illustrative purposes and not as defining the scope of the invention.

160 grams of maleic anhydride are mixed with 120 grams of linseed oil fatty acids and heated to about 360 F. The heating is continued at this temperature for about 45 minutes and glycerin is then added slowly and a part at a time until 103 grams of' the glycerin" have been added. During the addition of the glycerin the temperature is held at about 360 F. and after the addition this temperature is still held until a clear cold bead may be drawn. The solution is then thinned with a suitable solvent for instance solvent naphtha and butyl alcohol. This solution is then available for use as a liquid coating composition or for the addition of other ingredients in making a varnish, lacquer or other such material.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1, The method of producing soluble, oil acidmodified polyhydric alcohol-polybaslc acid resins, which comprises heating essentially maleic acid and the acids obtainable upon hydrolysis of linseed oil at elevated temperatures in the substantial absence of free glycerol until reaction between the acids has taken place, and then adding glycerol to the acid mass and continuing the reaction until a homogeneous, soluble resin is obtained.

2. The method of producing soluble, oil acidmodified polyhydric alcohol-polybaslc acid resins, which comprises heating essentially maleic acid and the acids of linseed oil at elevated temperatures in the substantial absence of free glycerol until reaction between the acids has taken place, and then adding a quantity of glycerol sulllclent to neutralize the acids and continuing the heating until a-homogeneous oil-soluble resin is obtained.

3. The method of producing oil soluble, oil acid-modified polyhydric alcohol-polybasic acid resins, which comprises heating essentially maleic acid and the free ends of linseed oil at approximately 380 F. for at least about 45 minlinseed oil acid resin produced in accordance with utes in the substantial absence of tree glycerol, the process of claim 1. a 4 and then adding thereto a quantity of glycerol 5. Anoil-soluble glycerol-maleic acid-linseed substantially equivalent to the total amount of oil acid resin fi'roduced in accordance with the 5 acids angflconflfiflng theuhegting anti! a homoprocess oi claim 2.

geneous -so e resin 0 tame JAMES VICTOR HUNN' 4. A soluble polyhydric alcohol-maleic 'acide I. CERTIFIUATE OI, CORRECTION, Patent no. 2,157,616. v November 22; 1938;

- JAMES VICTOR m'nm. It is nere by certified that error appearsin theprinted"specification I of the above numbered patent requiring correction as follows: Pae 1'. second column, line 5 5', o laim 5 for the word l'ends" resdacids; and-'thatthe said Letters Patent should be read with this correction therein that the? same may conform to the'record of the case inthe Patent Office.

signedand sealpdithis16th dayof January, A. c.1911);

' Henry Van Arsdale, Acting Commissioner of Patents. 

